I dont think that is what the case is at all. I think that they have a batch of poor or non heat treated rods that made it into production. They have decided that the rods are more than satisfactory for a normally asperated motor. They may even be okay in the turbo but they have had issues there so they are doing somthing about those motors. They are essentially blaming it on the MPI turbo over boosting the motor which should never happen due to the EABC. It seems like they found the perfect way to phrase it so they look like they are taking care of the customer while shifting blame to the turbo aspect.
To my knowledge there has not been a failure in this motor for any N/A ones. Its just the turbo's ones. And this needs to be stressed again: not all the 2016 motors have bad rods. Not even all the late 2016 motors have bad rods it has been discovered. Just some of them and I guess the problem for Yamaha is figuring out who got them. They have decided to just replace all the turbo rods just in case. We will never know but it would be interesting to know how many actually have the unheat treated rods.